Painting problem when using pen in Blender
I'm back. Believe me or not I've been looking for a solution for weeks but I found a solution today just a few hours after I posted this question. So, now I'm sharing it:

Because of one of the updates, Win10 doesn't treat legacy apps and modern apps which specifically designed for pen in the same way anymore. I think this is why I have never faced any issue in many apps (such as Krita and GIMP) but Blender. (Blender is legacy but not GIMP? LOL I don't get it, too.) There is a way to disable this behavior.

Solution


Run cmd
Type this and enter: reg add HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Pen /v LegacyPenInteractionModel /t REG_DWORD /d 1 /f


This will make it! If you have any problem with pen in future and want to go back use this command: reg add HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Pen /v LegacyPenInteractionModel /t REG_DWORD /d 0 /f

Btw, yes... it really is a BIG mistake not to put an option for this in the control panel. I wanna swear to Microsoft but I don't know if it's allowed here. So... shame on you MS! It took me weeks to just find this solution.

[Source: https://www.reddit.com/r/Windowsink/comments/8508fi/controlling_pen_behavior_in_windows_10/ ]

Edit

Addition:

It seems this command breaks pressure sensitivity. I solved it as well:


Go back with second command I mentioned above
Run regedit and go to HKEY_CURRENT_USER\Software\Microsoft\Wisp\Touch, set PanningDisabled to 1.
If there still is any issue, install/repair WinTab (https://www.microsoft.com/en-us/download/details.aspx?id=49498 download and install Wintab_x32_1.0.0.20.zip or Wintab_x64_1.0.0.20.zip depending your system arch)
If it still occurs, go run first command again.


Now, I can draw without any latency and pressure sensitivity works perfectly!